I am running Thunderbird Daily V95.0a1 (another person assisting me with the issue has identified that the issue is present in Thunderbird Daily V94.0a1 as well) on Linux (Fedora F34) and I am having an issue with Mails from several mail lists, whereby when browsed in the inbox they are fine, but when the message filters I have for the two mail lists moves the mails to relevant local folders, some of the mails in both folders are corrupted in that they show hieroglyphics. If I look at the source of the corrupted mails they show the headers, etc, from several other emails from the same folder, but those emails are still visible in the folder. A repair of the offending folders rectifies the issue, but only if I am in the folders viewing the list of emails, if I am in another folder and run the repair on the corrupt folder it seems to do nothing. I can even be browsing one of the corrupt emails, run the folder repair, and see the issue get resolved in front of me. I have around 45 local folders and associated message filters moving mails to them, but the issue has only ever occurred on two of them, being mails from the Fedora and libreoffice mail lists. Is it possible the mail lists are doing something under certain circumstances (given that it doesn't happen on all mails from the two mail lists) that Thunderbird is not coping with?